Metering molten metals



Oct. 5, 1965 A. BREDE m, ETAL METERING MOLTEN METALS Filed Aug. 13, 1962 INVENTORS. ALEXANDER Baa-0e, 111

y ELVIN E.TUTTLE ATTORNE Y5 United States Patent 3,209,948 METERENG MOLTEN METALS Alexander Erede III and Elvin E. Tuttle, Lansing, Mich,

assignors, by mesne assignments, to Motor Wheel Corpcration, Akron, Ohio, a corporation of Ohio Filed Aug. 13, 1962, Ser. No. 216,349

4 Claims. (Cl. 222-1) This invention relates to dispensing measured quantities of liquids and in particular to a method and an apparatus for dispensing measured increments of molten metal from a large capacity holding pot into smaller capacity hand ladles to pour centrifugal castings.

The objects of this invention are to provide a method and an apparatus by which liquids are dispensed in accurate weight or volume increments; that are simple and convenient; that are especially adapted to transfer measured portions of molten metal from a large capacity holding pot to a smaller capacity hand ladle; and that eliminate tipping the heavy, bulky holding pot while dispensing molten metal that originates from the bottom of the holding pot. The method is especially applicable to the metering, by weight, of liquids which do not lend themselves to the usual weighing methods. For example, liquid metals, hard to handle because of their high temperature, or acids, hard to handle because of their corrosive nature and toxic fumes.

In the drawings:

FIGS. 1 and 2 are schematic showings of an apparatus for practicing the instant invention where measured weight increments of molten metal are transferred to a hand ladle.

FIGS. 3 and 4 schematically show a modification of FIGS. 1 and 2 where measured volume increments of molten metal are transferred to the hand ladle.

More particularly, in FIG. 1 a primary receptacle or large capacity holding pot 6, made of suitable refractory material, is filled with molten metal 7 to a height 14 level with pouring lip 8. Pouring lip 8 communicates with the bottom of holding pot 6 through pouring spout 9. A secondary receptacle or hand ladle 10 which may be used to pour castings, is positioned to receive molten metal that fiows over the pouring lip 8. A bucket 12, also constructed of suitable refractory material, is positioned in the open end of holding pot 6 and floats partially immersed with the molten metal at the level of pouring lip 8. The molten metal displaced by the bucket raises the level of the same in the pot 6, the excess molten metal runs out of spout 9 and causse the level of molten metal to remain at the level of lip 8.

When a weight W (FIG. 2) is placed in bucket 12, the bucket moves further down into the molten metal to displace an incremental portion of molten metal over pouring lip 8 and into hand ladle 10. In accordance with Archimedes principle, bucket 12 is bouyed up by the molten metal with a force equal to the weight of the displaced molten metal. Since the additional weight W is supported by the molten metal an equal weight of molten metal W has been displaced over pouring lip 8 into hand ladle 10. To transfer additional increments of molten metal from holding pot 6, additional weights are added to bucket 12, each additional weight displacing an equal weight of molten metal into hand ladle 10. Of course, different hand ladles or even the mold itself may be used to receive each incremental portion of molten metal. Like or different weights may be added to transfer like or different measured increments of molten metal until bucket 12 sinks to the bottom of holding pot 6. Bucket 12 is then lifted from holding pot 6 and the holding pot is refilled.

Any convenient apparatus can be used to add additional weights gently. For example, the weights may be interlocked, as the links of a chain, suspended above the bucket and lowered by increments into the bucket. Additionally, suitable means may be provided for stabilizing the vertical movement of the bucket within the molten metal.

FIGS. 3 and 4 show slight modifications in the apparatus shown in FIGS. 1 and 2 whereby molten metal may be transferred over the pouring lip 8 into hand ladle 10 is measured volume increments. A fluid cylinder 16 is arranged above and partially within bucket 12 so that piston 18 engages the bottom of bucket 12. Piston 18 is actuated by fluid supplied through inlet 20 into expansion chamber 22. When fluid is admitted into chamber 22 through inlet 20, piston 18 will move bucket 12 downward into the molten metal to displace molten metal over the spillway or pouring lip 8 into hand ladle 10. The volume of molten metal transferred to hand ladle it) is equal to the additional volume of bucket 12 immersed in the molten metal with each downward movement of piston 18. Assuming the fluid supplied to chamber 22 is incompressible, the change in immersed volume of bucket 12 will be proportionate to the change of volume in the expansion chamber.

Moreover, bucket 12 could be eliminated and piston 18 could contact and project into the molten metal directly in which case that portion of piston 18 which is immersed in molten metal would be made of suitable refractory material. With such an arrangement, volume increments of molten metal displaced would be equal to the volume changes in the expansion chamber 22. The volume increments can be controlled precisely by a suitably calibrated scale to indicate either piston or bucket volume displacement. Alternatively, measured volumes of incompressible fluid may be supplied to chamber 22.

In light of the foregoing, any liquid can be dispensed in accurate increments of weight or volume regardless of the density of the liquid. The quantity of liquid dispensed is easily controlled by adding different sized weights or varying the volume of piston or bucket displacement. In the production of brake drums by a centrifugal casting process, an accurate and convenient method and apparatus are especially desirable since the cost of a drum is based in part on the weight of metal used to cast it. When the instant invention is used to measure molten metal for centrifugal castings, the need for moving and tipping the heavy, bulky holding pot to pour molten metal is eliminated while the desirable feature of dispensing molten metal from the bottom of the holding pot is retained. Additionally, the exposed surface of the pouring lip is relatively small, thus reducing the chance of oxidation, and when molten metal is dispensed by weight increments, accuracy is not affected by erosion of materials contacting the molten metal.

We claim:

1. Apparatus for dispensing a given weight of molten metal comprising a holding pot initially containing a weight of molten metal in excess of said given weight, said holding pot having an overflow outlet communicating with the interior of said pot, and a float buoyantly suspended in said pot by said molten metal with the surface of the molten metal level with said outlet, said holding pot having an upwardly facing opening at its upper end for receiving said float therethrough for buoyantly controlled vertical movement of said float in said pot, said float comprising a bucket-like member adapted to support while buoyant in the molten metal one or more of a plurality of objects of known predetermined weight severally or cumulatively selected as required to equal said given weight, said float having an open upper end adapted to receive the selected object or objects for placement on said float to thereby gravitationally move said float downwardly in said molten metal and thereby displace from LED said pot via said outlet a weight of molten metal equal to the weight of said selected object or objects.

2. Apparatus as set forth in claim 1, wherein said holding pot is made of refractory material, said overflow outlet comprises a pouring lip disposed outside said upper end opening of said pot and a pouring spout extending from said lip downwardly along said pot whereby said pouring spout connects said lip with the bottom of the interior of said holding pot, and said float comprises a refractory bucket having an upwardly facing opening at its upper end communicating with the interior thereof and adapted for receiving said selected object or objects for placement in the interior of said bucket.

3. The method of dispensing a given weight of molten metal in predetermined weight increments from a holding pot adapted to contain a weight of the molten metal in excess of said given weight and having an outlet which communicates with the interior of said holding pot comprising the steps of (1) placing at least said given weight of molten metal in said pot,

(2) placing on said molten metal a float adapted for immersion therein within said pot to bring said molten metal level with said outlet, and

(3) sequentially adding objects respectively equal in Weight to said Weight increments to said float to cause gravitationally induced progressive immersion of said float in said molten metal to sequentially displace said predetermined weight increments of molten metal from said pot via said outlet.

4. A method of dispensing a given weight of liquid from a receptacle adapted to contain the liquid in an 4 amount in excess of said given weight of liquid and having an overflow outlet for establishing the maximum liquid level in the receptacle, comprising the steps of (1) filling said receptacle with the liquid to be dispensed in an amount sufficient to cause the liquid to be level with said outlet when a member as recited in step (2) is floated in said liquid,

(2) floating a liquid displacing member in said liquid contained in the receptacle,

(3) selecting one or more of a plurality of objects of known weight as required to provide an object or objects having a weight equal to said given weight, and

(4) placing said selected one or more objects on said member to gravitationally induce downward movement of said member in said liquid until said member as so increased in weight reaches a stable buoyant position in said liquid whereby said member during said downward movement simultaneously displaces and overflows the liquid from said receptacle via said outlet to thereby dispense said given weight of the liquid.

References Cited by the Examiner UNITED STATES PATENTS 8/16 Hart 141-245 3/49 Petersen 222-319 X 

1. APPARATUS FOR DISPENSING A GIVEN WEIGHT OF MOLTEN METAL COMPRISING A HOLDING POT INITIALLY CONTAINING A WEIGHT OF MOLTEN METAL IN EXCESS OF SAID GIVEN WEIGHT, SAID HOLDING POT HAVING AN OVERFLOW OUTLET COMMUNICATING WITH THE INTERIOR OF SAID POT, AND A FLOAT BUOYANTLY SUSPENDED IN SAID POT BY SAID MOLTEN METAL WITH THE SURFACE OF THE MOLTEN METAL LEVEL WITH SAID OUTLET, SAID HOLDING POT HAVING AN UPWARDLY FACING OPENING AT ITS UPPER END FOR RECEIVING SAID FLOAT THERETHROUGH FOR BUOYANTLY CONTROLLED VERTICAL MOVEMENT OF SAID FLOAT IN SAID POT, SAID FLOAT COMPRISING A BUCKET-LIKE MEMBER ADAPTED TO SUPPORT WHILE BUOYANT IN THE MOLTEN METAL ONE OR MORE OF A PLURALITY OF OBJECTS OF KNOWN PREDETERMINED WEIGHT SEVERALLY OR CUMULATIVELY SELECTED AS REQUIRED TO EQUAL SAID GIVEN WEIGHT, SAID FLOAT HAVING AN OPEN UPPER END ADAPTED TO RECEIVE THE SELECTED OBJECT OR OBJECTS FOR PLACEMENT ON SAID FLOAT TO THEREBY GRAVITATIONALLY MOVE SAID FLOAT DOWNWARDLY IN SAID MOLTEN METAL AND THEREBY DISPLACE FROM SAID POT VIA SAID OUTLET A WEIGHT OF MOLTEN METAL EQUAL TO THE WEIGHT OF SAID SELECTED OBJECT OR OBJECTS. 